1. Field of the Invention
This invention relates to a seat reclining apparatus used for vehicles, which allows the back of a seat to be pivoted with respect to the seat cushion.
2. Description of the Related Art
A conventional seat reclining apparatus used in vehicles comprises a round casing and a round cap, which are capable of rotating with respect to each other. Generally, the round casing is attached to the base plate of the seat cushion, while the round cap is attached to the arm plate of the back, and a driving shaft penetrates through the round casing and the round cap. Lock gears are placed in the round casing, and an inside gear is formed along the inner rim of the round cap. By causing the inside gear to be meshed with the lock gears at a prescribed position, the mutual rotation between the round casing and the round cap is stopped. The engagement between the lock gear and the inside gear is released by rotating the driving shaft to retract the lock gear via a cam plate.
The round casing and the round cap are assembled together, and the periphery of the assembled body is covered with a binding member so as not to separate from each other.
The ends of the binding frame are caulked in such a manner that the round casing and the round cap are still allowed to rotate with respect to each other.
Then, the base plate is welded to the round casing, and the arm plate is welded to the round cap.
Since the conventional seat reclining apparatus in use for vehicles requires the caulking and welding steps, the assembling efficiency is not sufficiently high. In addition, the appearances of both the reclining apparatus itself and the reclining seats using this apparatus are unsatisfactory.
The present invention was conceived by solving these problems in the prior art. It is one of the objectives of the invention to provide a seat reclining apparatus for vehicles that can improve the assembling efficiency and the appearances of both the seat reclining apparatus itself and the reclining seat using it.
In order to achieve the objective, in one aspect of the invention, a seat reclining apparatus for a vehicle includes a casing having a round recess and a mount extending from the rim of the round recess, and a cap having a fringe that fits into the round recess. A driving shaft penetrates through the casing and the cap in the center of the cap. A binding frame holds a portion of the fringe of the round cap and at least a portion of the periphery of the casing together, in such a manner that the cap can rotates relative to the round recess of the casing. Lock gears are placed in the round recess of the casing, and a toothed gear (which may be referred to as an inside gear) is formed along the inner face of the fringe of the cap. The seat reclining apparatus also has a lock mechanism, which generally allows the lock gears to be meshed with the inside gear of the cap in order to fix the casing and the cap at a selected position. The lock mechanism is connected to the driving shaft. When releasing the engagement between the lock gears and the inside gear, the lock mechanism drives the driving shaft to pull the lock gears toward the center of the recess.
The mount of the casing functions as either a base plate or an arm plate. If the mount is fixed to the seat cushion, it functions as a base plate. If the mount is fixed to the seat back, it works as an arm plate.
The seat reclining apparatus further has an arm plate, and a coil spring for forcing the coil spring in a predetermined direction. In this case, the mount of the casing functions as a base plate, and the arm plate is fixed to a seat back. Then, the coil spring pushes the arm plate toward the front end of the seat cushion.
Preferably, the binding frame is horseshoe (or U-shaped) so as to correspond to the outline of the casing. The binding frame has a groove along the curve. The groove receives a portion of the periphery of the casing and a portion of the fringe of the cap. The binding frame may have expanded areas at both ends, which also correspond to the outline of the casing, and a hole is made in each of the expanded areas.
Since the mount of the casing functions as a base plate, the welding step, which was required in the prior art to secure the casing to a separate base plate, is eliminated. Consequently, the assembling process can be simplified, and an appearance is greatly improved.
The casing and the cap are held together by a binding frame in such a manner that they are still capable of rotating relative to each other. The periphery of the casing and the fringe of the cap are simply inserted into the groove of the binding frame. Thus, the structure and the appearance of the seat reclining apparatus are improved, and at the same time, the assembling process is simplified.
In another aspect of the invention, The binding frame has substantially the same shape as the casing, but has an opening that receives the cap. The binding frame has a fold-back along a portion of its periphery. The edge of the fold-back is either straight or curled so that the casing and the fringe of the cap are held together by the fold-back, while being capable of rotating relative to each other.
The fold-back may be formed along the entire periphery of the binding frame so that the whole area of the mount of the casing is held. Preferably, the entire edge of the fold-back is curled.